Biomedical subjects

M Diestelhorst

Publications and source records attributed to M Diestelhorst.

14 recordsLinked to original sources

PubMed1992

Effect of dexamethasone 0.1% and prednisolone acetate 1.0% eye drops on the blood-aqueous barrier after cataract surgery: a controlled randomized fluorophotometric study.

Using non-invasive anterior chamber fluorophotometry, we performed a double-blind, randomized clinical trial on the effects of dexamethasone 0.1% and prednisolone acetate 1.0% eye drops on the blood-aqueous barrier after phacoemulsification and posterior chamber lens implantation. Twenty patients received one of the preparations topically to the surgically treated eye 5 times daily for a period of 5 days, beginning the day after surgery. Patients chosen for the study had no history of eye disease other than senile cataract nor of systemic diseases influencing the eyes. No other steroids or non-steroidal anti-inflammatory drugs were given before or during the investigation. The fluorometric data measured 5 days after surgery show a lower mean concentration of fluorescein in the dexamethasone alcohol 0.1% treated group compared with the prednisolone acetate 1.0% treated group. The difference is statistically not significant. The clinical assessment of postoperative ocular inflammation did correlate with the fluorophotometric measurements. The results of the study indicate that although dexamethasone is the more potent anti-inflammatory agent, with a better binding affinity to glucocorticoid receptors, we are--with the number of cases measured--unable to demonstrate any difference in the efficacy in protecting the blood-aqueous barrier after cataract extraction and posterior chamber lens implantation to prednisolone acetate.

Administration, Topical↗

PubMed1992

Does aqueous humor secretion decrease with age?

Aqueous humor flow was calculated during day-time in 148 healthy volunteers and 75 older patients using the Fluorotron Master II anterior chamber protocol (Coherent, Palo Alto, USA). Healthy volunteers as well as patients had no history of ocular pathology, surgery or laser treatment. Slitlamp examination revealed no ocular pathology. Hypertension, diabetes, local and systemic drug therapy, neoplasia, kidney or liver disease, contact lens and ocular trauma were excluded. Mean age of volunteers was 26.5 +/- 3.8 years; age of patients: 65.5 +/- 10.5 years. Aqueous humor flow during day-time in healthy volunteers in the OD: (mean +/- s.d.) 2.26 +/- 1.0 microliters/min, in the OS: 2.17 +/- 1.0 microliters/min, OS: 1.86 +/- 1.1 Ml/min. Correlation coefficient: r = 0.8. The mean aqueous humor flow in the older patients during day-time: OD: 1.91 +/- 1.1 microliters/min. Correlation coefficient: r = 0.54. The Mann-Whitney-U-test revealed a significant difference when comparing the right eyes of healthy volunteers with the right eyes of patients (p < 0.01). When comparing all left eyes the difference is also significant (p = 0.01). The results of the study underline, that the mean aqueous humor secretion does significantly decrease with age. However, the data show that there is only a slight decrease of flow of approximately 2.5% per decade. From the clinical point of view it should be concluded, that although the aqueous humor secretion does decrease with age, this is not of clinical importance, even in cases of glaucoma surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

[Effect of 0.1% dexamethasone and 1.0% prednisolone acetate eyedrops on the blood-aqueous humor barrier].

In a randomized, double-blind clinical trial we studied the protective effect of prednisolone-acetate 1.0% and dexamethasone 0.1% on the blood-aqueous barrier after cataract-extraction and posterior chamber lens implantation. Pre- and postoperative anterior chamber fluorophotometry was performed after i.v. administration of 10% fluorescein-sodium in 20 eyes of 20 patients of whom 16 finished the study (mean age 68.7 +/- 11.0; 13 female, 3 male). The topical application of either drug 5 times daily for 5 days did show a significant difference in surgery mediated disturbance of BAB in each group before and after phacoemulsification. However, when comparing the effect of the two drugs with each other, a difference could not be detected (p = 0.35). To attain a statistical 95% probability that there is no significant difference between the two treatment groups, a number of 690 patients would have had to be investigated. The results can be interpreted as to be due to a better cornea penetration of prednisolone-acetate which compensate the higher glucocorticoid-potency and receptor-affinity of dexamethasone. The untreated fellow-eyes did not reveal a significant difference between the pre- and postoperative anterior chamber fluorescein-concentrations in either treatment group. Anterior chamber fluorophotometry is able to demonstrate the potency and influence of both prednisolone-acetate 1.0% and dexamethasone 0.1% eye-drops on the BAB following phacoemulsification and IOL-implantation. The difference of both drugs does not seem to be of clinical importance in this context.

Aged↗

PubMed1992

[1,3,7-trimethylxanthine. Effects on circadian aqueous humor dynamics in probands].

Anterior chamber fluorophotometry (Fluorotron Master II, Coherent, Palo Alto, Calif.) was used to investigate the influence of 1,3,7-trimethylxanthin on the circadian rhythm of aqueous humor secretion in two age-, race- and sex-matched groups of healthy volunteers. In ten males and ten females (mean age 27 years), aqueous humor secretion was measured over 24 h at: 0800, 0900, 1000-1400, 1500, 1600-2000, 2100, 2200-0200, 0300, and 0400 hours. Flow was calculated using the Yablonsky protocol of Fluorotron Master II. In group I all volunteers received about 800 mg trimethylxanthin in the form of caffeinated coffee between 2200 and 2300 hours. In group II volunteers went to sleep at 2300 hours. Sleep was only interrupted for measurements. During the daytime the mean aqueous humor flow was the same in both groups (0800 to 2200 hours) (Student's t-test): Group I (n = 10) RA 2.27 +/- 0.70 microliters/min LA 2.25 +/- 0.74 microliters/min Group II (n = 10) RA 2.23 +/- 0.73 microliters/min LA 2.06 +/- 0.64 microliters/min During the night the mean aqueous humor flow decreased in both groups (0200 to 0400 hours): Group I: RA 1.99 +/- 0.74 microliters/min delta flow = -12% LA 1.93 +/- 0.75 microliters/min Group II: RA 0.97 +/- 0.50 microliters/min delta flow = -56% LA 0.97 +/- 0.48 microliters/min The difference between groups was statistically significant (P = 0.01, t-test for unpaired samples). There was no significant change in mean aqueous humor flow between the daytime vs night in group I (P < 0.5).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

Perimetric follow-up in glaucoma with a reduced set of test points.

The global mean defect (GM) is probably the most useful visual field index for glaucoma follow-up. We compared 50 regional subsets of test locations to estimate the GM. Using the data on 424 automated fields of 257 patients with either primary open-angle glaucoma or ocular hypertension, we calculated the partial sample error of the regional mean defect as compared with the GM. In many regions, the measured sample error was greater than expected for a representative sample of points. Some sample errors were up to 5 times larger (regions "upper hemifield" and "lower hemifield"). Only a few subsets proved to be representative of the whole field, namely, regions "ring 3" (10 degrees-15 degrees), "ring 4" (15 degrees-20 degrees) and "ring 5" (20 degrees-25 degrees). The use of such programs for follow-up is very accurate for staging. Moreover, theoretical calculations reveal that trend analysis is even more significant if the reduction in examination time is combined with a proportional increase in examination frequency.

Adolescent↗

PubMed1991

The effect of trabeculectomy on the aqueous humor flow of the unoperated fellow eye.

Computerized anterior-chamber fluorophotometry was used to investigate the effect of unilateral antiglaucomatous trabeculectomy on the dynamics of aqueous humor in the unoperated fellow eye. In 14 patients with bilateral primary open-angle glaucoma, pigmentary glaucoma or exfoliation glaucoma, antiglaucomatous trabeculectomy was performed in one eye in which medical management of glaucoma had failed. The fellow eye in all patients had a well-defined history of glaucoma and had been treated with different sorts of medication. The medical management of the unoperated fellow eyes was continued throughout the study. Aqueous humor flow was measured in these eyes prior to surgery and on the 5th day after trabeculectomy. Systemic medication was discontinued from 48 h prior to surgery until second fluorophotometry. The average postoperative flow in the fellow eyes increased from 2.56 to 2.92 microliters/min (P less than 0.05%, paired t-test). The increase in flow in the fellow eyes was independent of topical antiglaucoma medication and of the diurnal rhythm of aqueous humor dynamics. The results of the study indicate that filtration surgery in one eye triggers a CNS-mediated, reflective increase in aqueous flow to maintain physiological stability in the anterior chamber of the surgically treated eye. Since this CNS reflex on aqueous humor dynamics affects both eyes, the clinical observation of intraocular pressure (IOP) dysregulation in the unoperated fellow eye following unilateral trabeculectomy is now understandable.

Adult↗

PubMed1991

The effect of isosorbide-mononitrate eye drops on the human intraocular pressure and aqueous humor dynamics.

In a randomized, double-masked, single drop study the effect of topical isosorbid-mononitrate (ISMO) 0.5% eye drops, the main metabolite of isosorbid-dinitrate, widely used in the treatment of coronary heart diseases, was studied in patients suffering from open angle glaucoma or ocular hypertension. There was no statistically significant IOP change within 8 hours posttreatment after topical administration of ISMO 0.5%. There were no side effects after application of the ophthalmic solution of ISMO 0.5%. There were no significant changes in blood pressure and pulse rate either. A 2% ophthalmic solution of ISMO was investigated with respect to a response on the aqueous humor dynamics in 10 healthy volunteers. Anterior chamber fluorophotometry revealed a mean increase in aqueous flow of 39% within 3 hours after topical application (P less than 0.01). However, in comparison to the placebo treated fellow eyes there were no statistical significant difference in aqueous humor flow during the time of investigation. There was a statistical significant reduction of IOP during the same time period (p less than 0.03) in all treated eyes.

Aqueous Humor↗

PubMed1991

The effect of flurbiprofen 0.03% eye drops on the blood aqueous barrier in extracapsular cataract extraction with IOL implantation.

Preoperative and postoperative anterior chamber fluorophotometry were performed after intravenous administration of fluorescein sodium in patients undergoing extracapsular extraction and posterior chamber lens implantation. The topical application of aqueous flurbiprofen sodium 0.03% solution before and after surgery significantly decreased the surgery mediated disturbance of the blood aqueous barrier as compared to vehicle application (placebo controlled). In contrast to similar studies, cortical steroids were not given topically or systemically to either group of patients during the study. The present fluorophotometric results correlate well with slitlamp biomicroscopy of postoperative inflammation. The data of this study indicate that flurbiprofen ophthalmic solution is effective in protecting the blood aqueous barrier (BAB) in human eyes during cataract surgery and IOL implantation.

Administration, Topical↗

PubMed1991

[Effect of cataract extraction on aqueous humor dynamics in patients with senile cataract. A prospective fluorophotometric study].

The influence of posterior chamber lens implantation on the aqueous humor dynamics was investigated using anterior chamber fluorophotometry before and 9 weeks after cataract extraction and IOL implantation. Thirty-four patients finished the protocol. Patients with preexisting glaucoma or those having a history of ocular or systemic inflammation were excluded from the study, as were those taking topical or systemic drugs with potential influence on the aqueous humor dynamics. Nine weeks after IOL implantation a mean increase in aqueous humor flow was noted. This increase was highly significant (p less than 0.01, Student's paired t-test). There were no significant changes in aqueous humor dynamics in the unoperated fellow eyes which served as controls. The significant difference in aqueous humor flow 9 weeks after cataract extraction and IOL implantation indicates that the liberation of prostaglandins may cause an increase in the ease of outflow facility.

Aged↗

PubMed1991

[Influence of cataract and posterior chamber lens implantation on the dynamics of the aqueous humor. Prospective study in fluorophotometry].

The influence of posterior chamber lens implantation on the aqueous humor dynamics was investigated using anterior chamber fluorophotometry before and 9 weeks after cataract extraction and IOL implantation. 34 Patients finished the protocol. Patients with preexisting glaucoma or those having a history of ocular or systemic inflammation were excluded from the study, also those taking topical or systemic drugs with potential influence on the aqueous humor dynamics. 9 weeks after IOL implantation, a mean increase in aqueous humor flow was notified. This increase was highly significant (p less than 0.01, Students paired t-test). There were no significant changes in aqueous humor dynamics in the unoperated, fellow eyes which served as controls. The significant difference of aqueous humor flow 9 weeks after cataract extraction and IOL implantation indicates that the liberation of prostaglandins may cause an increase of outflow facility as well as pseudo-facility.

Aged↗

PubMed1990

[Stereospecificity of lowering intraocular pressure using a locally administered carbonic anhydrase inhibitor].

As MK-417, the S-enantiomer of the racemic compound MK-927, is the more active enantiomer in vitro, the potential differential ocular hypotensive activity was investigated in patients. The 1% concentration was chosen as the basis for comparison, as preliminary data indicated that the concentration would fall relatively steeply on the dose-response curve. This was a two-center crossover study of 1% MK-417, 1% MK-927, and placebo (common vehicle) in 27 patients with bilateral, relatively symmetric primary open-angle glaucoma or ocular hypertension. Following a washout period for ocular hypertensive therapy, IOP had to be greater than or equal to 23 mmHg at 10:00 o'clock with IOP difference between eyes less than or equal to 6 mmHg. Treatment days were separated by a 1-2 week washout period. IOP was measured at 9:30. At 10:00 patients received the test drug in one designated eye and placebo in the other eye. IOP was measured at 1, 2, 4, 6, and 8 h after the dose. IOP and the percentage of change in IOP from 30 min before the dose in the active drug-treated eye shows that MK-417 is slightly more potent than MK-927 in this patient model.

Adult↗

PubMed1989

The effect of betablockers with and without ISA on tonographic outflow facility.

The response of two ophthalmic betablockers, Timolol (without ISA) and Pindolol (with marked ISA), on IOP and tonographic outflow facility was investigated in a single-blind clinical study on 20 patients with glaucoma or ocular hypertension. In two treatment groups, ten patients each, in a randomized order IOP and tonographic outflow facility measurements were performed before and 2 hrs after drug application. Timolol reduced IOP by 6.8 mm Hg and Pindolol eye drops by 4.5 mm Hg. Both topically applied betablockers did not influence tonographic facility of outflow. It is concluded that the intrinsic sympathomimetic activity of an ophthalmic betablocker has no effect on outflow facility of aqueous humor.

Aqueous Humor↗

PubMed1989

The intraocular pressure response of human atrial natriuretic factor in glaucoma.

In an open label, single dose study on ten glaucoma patients with bilateral untreated IOP levels exceeding 30 mmHg the effects of 100 micrograms human atrial natriuretic factor (HANF) on IOP, systolic blood pressure, pulse rate and serum electrolytes were investigated. The intravenous application of HANF decreased IOP over more than 8 hrs. The magnitude of IOP reduction in this study was in the range of 4-7 mmHg. There was no significant change in blood pressure, pulse rate or serum electrolytes. The verified, yet still limited efficacy of HANF on IOP in glaucoma warrants further investigations.

Atrial Natriuretic Factor↗

PubMed1989

[The intraocular pressure lowering effect of human atrial peptide].

The human atrial natriuretic factor (hANF) is a cardiovascular hormone, which promotes renal sodium secretion in response to increases in extracellular fluid volume and atrial pressure. It regulates sodium and volume homeostasis. Specific receptors for hANF have been identified in the ciliary processes of rats and rabbits, which mediated a long-lasting reduction in intraocular pressure (IOP) after intra-atrial injection. In a series of 10 glaucoma patients with bilateral IOP elevations above 33 mmHg an i.v. bolus injection of hANF was administered and IOP was recorded before and over an 8-h period after injection. The human atrial natriuretic factor lowered IOP significantly. The potential of hANF as an antiglaucoma agent is discussed.

Atrial Natriuretic Factor↗